Drug repositioning: examining antipsychotic drugs and their anticancer effects

Cancer leads the list of causes of death worldwide, and the search for new and rapid treatment options for this disease has accelerated. New chemotherapeutic agents that inhibit tumor growth and proliferation are being introduced to the market; however, it presents various challenges, including the lengthy effectiveness of clinical trials, difficulty transitioning to phase 3 clinical stages, and high financial costs. A drug that had previously gained popularity in the market, has recently been repositioned for a different purpose, making it an excellent target for the treatment of several diseases. This review specifically focuses on the anti-cancer effects of repositioned antipsychotic medications that were studied for cancer treatment as well as their combination studies with other chemotherapeutic agents, using a literature search. A literature review covering the last 15 years was conducted using the PubMed (MEDLINE), Google Scholar, and Web of Science databases, with the keywords 'anticancer,' 'antipsychotic drugs,' and 'drug repurposing' used in combination. Studies that yielded productive results across broad historical ranges were included in the review. Initially, the correlation between schizophrenia patients and cancer was explored. Next, antipsychotic drugs with reported anticancer activities were identified, and their in vitro and in vivo anticancer mechanisms were revealed. Finally, the potential contributions and significance of these drugs in future therapeutic approaches were highlighted. In conclusion our literature search has revealed that antipsychotic medications can be useful in treating cancer.